Clock not running (was Re: RTEMS4.7 and its tool chain (Re: powerpc mvme5500 clock off by factor of 150))

Peter Dufault dufault at
Wed Mar 9 12:40:52 UTC 2005

On Mar 9, 2005, at 7:15 AM, Joel Sherrill <joel at> wrote:

> cpukit/score/cpu/powerpc/rtems/score/cpu.h has these:
> #define PPC_Set_decrementer( _clicks ) \
>   do { \
>     asm volatile( "mtdec %0" : : "r" ((_clicks)) ); \
>   } while (0)
> #define PPC_Get_decrementer( _clicks ) \
>     asm volatile( "mfdec  %0" : "=r" (_clicks) )
> Note that there is no & in the get.  Even the get and set timebase
> register don't have them.  Is this right?

I had checked that they matched before.  It fixed my problem.  I don't 
know if it is a gcc "feature" in 4.0 or what, and today I don't have 
time to think about it.  I've been up since Till found that problem 
last night getting my application running, and I'm planning to try 
things out at the customer site in a few hours.

Again, Till gets my "Hero of the Day" award.


Peter Dufault
HD Associates, Inc.

More information about the users mailing list